The family’s story began to unravel in late 1965 when the first of their children died. The Martinez de la Aguilar family lived in a small village in Spain, where the father, Andreas, worked as a laborer and the mother, Antonia, stayed home to care for their six children. There was never any extra money for small treats, and the family lived a modest life. Antonia sometimes wondered if moving to a larger Spanish city, like many of their neighbors had done, might mean a bigger house, a higher standard of living, and greater opportunities for their children.
She knew her two sons and daughter were happy in the village, playing with friends in the square and the surrounding fields. Still, she was excited about the prospect of a new life in the city of Mercier, believing it would mean better-paying jobs for her children as Spain became more industrialized. At the time, Spain was undergoing significant political and social transformation. The country was still under the rule of General Francisco Franco, who had been in power since the end of the Spanish Civil War in 1939.
Spain was largely isolated from the rest of Europe, but the government had started to modernize many cities and embrace foreign visitors, particularly along the Mediterranean coast. This led to a construction boom, with the government building social housing that was made available at very affordable prices. Antonia was excited about the move, although she worried her daughter Piedad might miss her friends. She believed that living in Mercier would secure a brighter future for all her children.
The family’s life took a tragic turn when their youngest child, a two-month-old baby, died suddenly from an unknown illness. The parents were devastated, but they tried to move on. Five years later, on December 4, 1965, their second-youngest child, a two-year-old boy named Mariano, also died. The children had all seemed to be in good health before their sudden demise.
Their bodies would develop a nasty rash, and marks that turned darker like bruises. They would also develop purple spots, accompanied by a fever, followed by blackouts and strong convulsions. Then, they would die. Within two weeks, three of the children had died, and the family was in shock.
The local doctor and authorities were puzzled by the mysterious deaths. Neighbors grew anxious, fearing a contagious disease or a strange virus transmitting from one sibling to another. As a result, they began to distance themselves from the family. The authorities acted quickly, sending the Martinez de la Aguilar family to the Provincial Hospital of Mercia for observation.
Initially, doctors thought the children may have died from a food intolerance, but tests found nothing unusual. The family was allowed to return home just in time for Christmas. However, two weeks later, on January 4, 1966, the youngest child, five-year-old Andreas, became ill and died. In less than a month, four of the six children had died, all presenting the exact same symptoms.
The deaths had a strange pattern: the children were dying in ascending order of age, and all seemed healthy before their sudden deaths. Still not knowing what was causing these strange and tragic deaths, doctors in Mercia removed the internal organs of Andreas and sent them to Madrid for analysis at the National Institute of Health. No presence of any virus was detected, so the organs were passed on to the Institute of Toxicology. Subsequently, the bodies of the four children were exhumed.
The toxicology report confirmed that, without doubt, all the children had been poisoned. There were traces of DDT and potassium cyanide. At the University of Mercia, doctors conducted experiments with 21 guinea pigs and some dogs to determine how much of the poison was needed to kill someone. They were unsure if the victims had unknowingly ingested the poison or if it had been given to them on purpose.
Following their experiments, they concluded that the children had been deliberately poisoned. They sent their findings to the Criminal Investigation Brigade. The first suspects were logically the parents. Andreas Martinez de la Aguila and his wife Antonia were arrested.
Antonia was in the advanced stages of pregnancy and was held in the maternity ward of the Son Dureta Provincial Hospital, while her husband underwent a mental health evaluation at the El Palmer Psychiatric Center. The news of the children’s deaths soon spread throughout Spain, catching the interest of a weekly publication named *El Caso*. This magazine, known for its coverage of strange occurrences and mysteries, sent a journalist to interview the Martinez de la Aguila children. All the surviving children were given a bed in the hospital so they could be looked after by their mother and observed by the police and medical staff.
The local priest was a regular visitor. The youngest child, Piedad, was a strange and quiet girl. She had been in charge of taking care of her little siblings when her parents were out of the house working. The journalist noticed that Piedad seemed oddly detached, and he wondered if she may have been responsible for killing her siblings.
An inspector devised a plan to see if this might be the case. When confronted, Piedad admitted to killing all four siblings but insisted that the first three were at her mother’s behest, while the last one was her own impulsive act. She explained her method of preparing the poison by combining metal cleaning tablets, especially those used for motorcycle parts, with rat poison. The lethal mixture was then poured into a glass of milk, which the children unknowingly consumed.
This toxic combination would have caused rapid death, explaining why the children had died within half an hour of becoming ill. Upon admission to the psychiatric hospital, Piedad began recounting five different versions of what happened, each more contradictory than the last. She persistently accused her mother of being the mastermind. Authorities believed that Piedad had poisoned her siblings in a calculating and malicious manner.
However, both police and medical professionals were unable to work out how such a young girl with only basic education managed to discover the lethal potential of household products. The authorities were initially skeptical of Piedad’s accounts and continued to investigate. As the eldest daughter, Piedad was expected to remain at home while her parents and elder brothers worked. She resented having to care for her younger siblings, who demanded the most attention.
She aimed to eliminate them all, hoping for a life free of responsibility. One journalist described her as “a girl of extraordinary cynicism or astonishing tranquility,” and noted her strange, ironic, and sly demeanor. The journalist also wrote that he believed Piedad was the sole author of the four deaths. Being a minor, Piedad couldn’t be formally charged and was instead placed under the custody of the juvenile protection courts.
She found solace in a convent in Mercia, which provided compassionate care and support for at-risk girls. Despite her confinement, she often had a sewing box by her side. The family’s name, however, continued to be in the press. The eldest brothers, Antonio and Manuel, started a singing duo, and a businessman took them on a tour of Spain.
This career did not last long. Antonio also tried to become a bullfighter, but again his attempts failed. As time passed, both Antonio and Manuel became known to the police for their unlawful activities. They were eventually arrested for the theft of a motorcycle, and a few years later, Antonio was found guilty of murdering a taxi driver and given a life sentence in prison.
The family’s story disappeared from the papers and from the minds of the Spanish people until 1978, when Antonio was again in the news. He was involved with 15 other inmates in a daring prison escape, having managed to dig a tunnel to freedom. However, they were caught again soon after. Tragically, the life of Señora Andreas Martinez de la Aguila and his wife Antonia continued to be blighted.
They were rejected by society and left with an internal void after the loss of five of their children and the terrible crimes of their daughter. Andreas lost his job but managed to find work as a refuse collector. However, he went blind and plunged his family into poverty. He sadly died a few years later.
The details of Piedad’s life after her internment are somewhat unclear. Some accounts suggest she embraced religious life, while others indicate that she returned to the streets and concealed her identity. The truth regarding her whereabouts and actions remained elusive as she attempted to conceal her past.